Udinese had taken the lead, but after Nicolas Opoku’s dismissal it was all downhill in a record-shattering 7-1 victory that puts Atalanta three points off leaders Juventus.
The most prolific side in Serie A took on the stingiest defence, as while the Orobici had scored 21 in eight rounds, the Friulani conceded only six. The main problem was that Udinese had only scored four as well, none of them away from home.
Duvan Zapata and Andrea Masiello missed out, with Jose Luis Palomino pulling out in the warm-up to make way for Rafael Toloi. There was some fatigue after a 5-1 Champions League thrashing at Manchester City midweek. The visitors had to do without Jens Stryger-Larsen on the wing.
Inevitably, the hosts poured forward, with Rodrigo Becao getting just enough on a Hans Hateboer cross to stop Luis Muriel tapping in at the near post.
However, Udinese were gifted their first away goal of the season with a howler from Simon Kjaer. The defender was caught in possession as the last man, allowing Stefano Okaka to go clear on goal and beat Pierluigi Gollini one-on-one.
Papu Gomez shrugged off Becao to force a Juan Musso save, then Josip Ilicic’s equaliser was flagged offside, but VAR showed he was level with the last defender when the Gomez through ball was released for him.
It was wide open, as Gollini stuck out a foot to deny Kevin Lasagna’s angled drive, but there was a crucial turning point.
Nicolas Opoku was already on a yellow card when he brought down Ilicic from behind for a penalty and inevitable second booking, reducing Udinese to 10 men. Luis Muriel converted the spot-kick, sending Musso the wrong way.
Atalanta were awarded another penalty, but it was revoked using VAR, because Becao’s arm was behind his back when the Gomez cross stuck his hand.
Ilicic did make it 3-1 soon after anyway, as Gomez’s attempt on a corner was charged down and the Slovenian fired in the rebound from seven yards.
Atalanta ran riot after the break. Papu Gomez was enjoying acres of space down the left flank, pulling back for Muriel to meet it at the back post.
He then tested Musso from a tight angle, but moments later Papu rolled a perfect assist across for Mario Pasalic to turn in from 10 yards.
Udinese had the strongest defence in Serie A, conceding only six goals in eight rounds, but almost let in their sixth in one afternoon when Ilicic’s curler bounced off the bar.
Musso was keeping the scoreline down, along with Pasalic somehow turning over a Musa Barrow cut-back from a couple of yards.
Samir’s clumsy sliding tackle on Muriel managed to create a chain reaction that left four players down on the ground and give Atalanta another penalty. Muriel recovered to convert for his hat-trick.
Seko Fofana tried to at least get a consolation goal, his strike fingertipped on to the bar by Gollini.
There was still time for Amad Diallo Traore, the younger brother of Sassuolo midfielder Junior Hamed Traore, to score on his debut, dribbling past Samir to drill low into the near bottom corner for 7-1.
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Sent off: Opoku 32 (U)